ROOTECH ACCURA 3300S, Руководство пользователя

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Page 42
Method 2: Calculation of Harmonics
Method 2 is used to obtain reactive power from apparent and active power, and the overall
apparent power by using calculation of vector apparent power.

=
T
a a a
dt t I t V
T
P
0
) ( ) (
1
,

=
T
b b b
dt t I t V
T
P
0
) ( ) (
1
,

=
T
c c c
dt t I t V
T
P
0
) ( ) (
1
c b a
P P P P
+ + =
arms arms a
I V S
=
,
brms brms b
I V S
=
,
crms crms c
I V S
=
2 2
a a a
P S Q
− =
,
2 2
b b b
P S Q
− =
,
2 2
c c c
P S Q
− =
,
c b a
Q Q Q Q
+ + =
2 2
Q P S
+ =
,
S
P
PF
=
a
a
a
S
P
PF
=
,
b
b
b
S
P
PF
=
,
c
c
c
S
P
PF
=
Note
P can be a positive or negative value, while Q is always a negative value.